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<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        var obj = {uname:"张三"}
        Object.defineProperty(obj,"age",{
            value:21,
            enumerable:true, //是否课枚举：是否可别遍历
            writable:true,//是否可写
            configurable:true,//属性是否可删除
        })
        // 检测是否能删除
        delete obj.age;
        console.log(obj);



    </script>
</body>
</html>